Each of two or more synonyms referring to nominal taxa with the same name-bearing type, or, in the cases of family-group and genus-group taxa, referring to nominal taxa with name-bearing types whose own names are themselves objectively synonymous.

Rigid, dermal structure resembling a tooth or bristle found in certain fish taxa, notably many neotropical catfishes. Also known as a dermal tooth and has a structure comparable to that of an oral tooth, with dentine surrounding a central pulp cavity covered by a superficial layer of enamel or similar material. Often more pronounced or extensively-distributed in […]

Small, spherical droplet of oil found within the yolk sac of fish larvae. There may be one or more present and the size, positioning, and colour are also variable meaning they can be useful in terms of taxon identification.